Perfluoroelastomers have achieved outstanding commercial success and are used in a wide variety of applications in which severe environments are encountered, in particular those end uses where exposure to high temperatures and aggressive chemicals occurs. These polymers are often used in seals for aircraft engines, in oil-well drilling devices, in semiconductor wafer manufacturing processes and in sealing elements for industrial equipment used at high temperatures.
Many perfluoroelastomer seals are filled with carbon black. However, an increasing number of end use applications require non-black seals. White fillers such as silica, barium sulfate, alumina and aluminum silicate are generally employed for such applications (U.S. Pat. Nos. 5,696,189 and 6,191,208 B1).
There are several different types of curing systems available for crosslinking perfluoroelastomers. Particularly preferred systems are i) bis(aminophenol)s (U.S. Pat. No. 6,211,319) and ii) compounds which decompose at curing temperatures to generate ammonia. It is believed that the ammonia reacts with nitrile group cure sites located on the perfluoroelastomer polymer chains to produce triazine rings, thus crosslinking the perfluoroelastomer (U.S. Pat. No. 6,281,296 and WO 200127194).
It would be desirable to have a non-black filled perfluoroelastomer composition which is curable with either a bis(aminophenol) or an ammonia generator compound and which yields a cured article having good physical properties, including compression set resistance.